It starts with a tingling sensation, almost like an electric jolt to the body. A heavy weight presses down upon the chest, rendering you immobile. You sense a presence in the corner of the bedroom. It moves closer and closer to your bed. You try to move or scream, but nothing happens. The shadow man just keeps lurching forward. Soon he’ll be upon you, and there is no telling what damage he’ll inflict.

For those with sleep paralysis, every night brings personal trauma. For The Nightmare, Room 237 director Rodney Ascher interviews eight people who have the disorder, asking them to thoroughly describe their nightly terrors. As victim testimony plays over the soundtrack in voice-over, Ascher recreates the nightmares through the use of actors, costumes, and low-budget special effects.

It is uncertain how one is meant to respond to the various reenactments. Visually, they have shoddy or cartoonish qualities and frequently inspire laughter more than fright. Whenever the shadow man makes an appearance, for example, he is clearly just an actor wearing a black jumpsuit and mask. It does not appear to be Ascher’s intent to strive for realism with these recreations. Instead, he seems to call attention to the ludicrous nature of these hallucinations. As it often is with nightmares, the experiences seem so authentic and frightening in the dream world, and it is only upon awakening and reviewing them that you realize their utter absurdity.

The Nightmare is not completely without its frights. The film’s sound design is particularly effective. Sometimes the soundtrack is burdened with an unnerving silence, and other times it blares with the shadow man’s demonic screeches. While this tactic provokes little more than jump scares, such a conventional horror technique still proves successful much of the time.

If there is one issue that proves detrimental to The Nightmare, it is the repetitive nature of the reenactments. Such a fault is exceptionally flagrant in the first half of the film, when Ascher provides the audience with only the most generic hallucinations experienced by sleep paralysis sufferers. While there are minor variations in each interviewee’s account, many of these nightmares play out in relatively the same manner. The afflicted awakens in the middle of the night, senses a presence in the room, and attempts to move or scream before it reaches the bed. As the film progresses, though, the victims start to regale Ascher with more colorful, specific hallucinations, which supplies the film with a renewed vigor.

The Nightmare never provides scientific inquiry into sleep paralysis, and the disease remains as much of a mystery as it was at the start. Far more of interest to Ascher is allowing the audience to have as much of a first-hand experience with the disorder as possible. Though The Nightmare drags at certain stretches, it sufficiently illustrates the horror that awaits the afflicted after they turn off the lights.